An excerpt from the book describes what happened in what was the third incident between Katsaka and trainer Ken Peters:

Peters had been waiting for Kasatka to touch his foot, the beginning of that particular behavior. He was about ten or fifteen feet down. Suddenly, he heard a killer whale vocalizing loudly. Peters described it as a distress vocalization or cry.

He later learned the wailing was from Kalia (Kasatka’s calf) screeching for her mother, presumably, from the other pool.

Kasatka instantly pulled her rostrum away from Peters’ feet. And then she grabbed his ankles, pulling him underwater for several seconds. When he resurfaced, she grabbed him again, this time “rag-dolling” her trainer violently by shaking him back and forth with her powerful neck muscles. Kasatka took him under again, for a minute or more.

Then, slowly and deliberately, as if performing a bizarre underwater pas de deux, the whale began to spiral upward with Peters’ foot in her mouth. She exhaled a cloud of white bubbles from her blowhole.

When they finally resurfaced, Tucker Petrzelka heard a shout for help. He slapped the water, trying to bring Kasatka back to stage. Matt Fripp grabbed the call-back device and deployed it while John Stewart slammed a metal bucket against the pool’s side. Kasatka was having none of it.

Her behavior continued and she continued to drag Peters around, while ignoring everyone else. After Kasatka finally finished, Peters is seen fleeing the pool with mangled feet in what looks like an understandable state of terror.

Peters stated that she gave no indication that she was about to go off, but later recalled Kalia crying backstage.

“I think she was trying to tell him, ‘Hey, I got to go take care of my kid … she’s calling for me, and I don’t want to perform,’” said Kirby, who believes Peters is lucky to be alive.

The footage was used as evidence in court by the Occupational Safety and Health Administration (OSHA) last year when it defended its decision to issue SeaWorld with a citation after Dawn Brancheau became Tilikum’s third victim. SeaWorld argued at the time that it was unaware that killer whales could be deadly …because who would have ever thought an apex predator could be deadly!?

SeaWorld is still defending itself and stated that everyone executed the response plan well and that Peters is still working there, despite what happened.

Sadly, cetaceans are seen under the law as mere objects without inherent rights and while husbandry practices may have improved some since we’ve been keeping them in captivity, they will never thrive the way they would in the wild and marine parks that stand to make a profit off of their suffering will continue to argue that they’re contributing to education and conservation efforts, all while inaccurately portraying what, or who, these amazing creatures really are.

Extremely smart, very large mammals, family/group oriented wild sentient beings are captured and put in tiny areas tantamount to a lifetime of solitary confinement . They are emotional beings kept from everything that is important and meaningful to them in their lives. They are cut off from what mentally keeps them happy and healthy. These communicative problem-solving beings are bored out of their minds! They develop skin and lung problems in these watery jail bathtubs we call tanks. They are sensitive to noise, and humans make lots of noise. We ignore their needs, making them perform inane, repetitive tricks for our entertainment and profit.
They get to see this happen to their offspring which makes it even worse.

And we wonder with surprise why they get upset and loose it and act out from time to time?

Its amazing that there haven't been more deaths and mishaps. It is a testament to their goodwill towards us that they behave as well as they do with constraint under these circumstances.

It's one thing to help a sick or injured being who has washed up on shore. But that being needs more of a sanctuary with others of its kind and not be performing tricks. (Another conversation.)

Killer whales (all whales), dolphins, porpoises are all sentient mammals, just like us. They have needs and wants and desires, just like us. If we truly respect and love them, we need to let them live their lives in the wild and appreciate them in their natural habitat. Period.

It will only get more and more prevalent as the days go by. Animals are aware of how completely disrespectful humans have become to other life and the planet. I don't keep pets and I don't support the juvenile idea of captivity for the sake of "education". Humans don't get my vote.